Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.mrao.cam.ac.uk/~jsy1001/dimmwit/tracking_mode.txt Дата изменения: Thu May 6 17:03:31 2004 Дата индексирования: Tue Oct 2 07:20:53 2012 Кодировка: Поисковые слова: http astrokuban.info astrokuban

Tracking Mode

With respect to tracking the image (using the green traffic light button),
yes, you can do this too - nice to see DIMMWIT being used creatively :)
When you are tracking, the red light button tells DIMMWIT to stop.
Again, some warnings:

1. If you do this, you won't be able to do your dark subtraction, because
you won't know where on the CCD the image is coming from at any
particular moment.

2. Your star images will appear to "jump" in the FITS file every time the
program decides to change the CCD region being read out. This is OK if
you're doing DIMM measurements because all you care about is the relative
motion of the two images, but see (3) below.

3. The tracking algorithm is very simple - it just tries to keep the brightest
pixel within itself in a constant position relative to its corner. So
if you have two stars of similar intensity in the readout region, it will
occasionally jump between them. So you have to make sure the region is
big enough that both star images are in the field in this situation,
or make sure one is significantly dimmer than the other.

4. It only works in slow 2D mode.

But doing this does the program no harm, so if you want, go ahead
and try it :)